EP2674585B1 - Lightweight acoustic muffler - Google Patents

Description

The present invention relates to a silencer for an exhaust system of an internal combustion engine, in particular of a motor vehicle. The invention further relates to an exhaust system with such a silencer and an internal combustion engine with such an exhaust system.

Silencers typically include a housing that encloses a muffler volume, and at least one inlet tube and at least one outlet tube. The muffler can then be fluidly connected to the rest of the exhaust system via the inlet pipe and the outlet pipe. The muffler may also comprise at least one holding element with which the muffler can be attached to a support structure, for example the internal combustion engine of a motor vehicle. In vehicle applications, it is common practice to lay the exhaust system along a subfloor of the motor vehicle. Since only comparatively little installation space is available in the underbody area, mufflers can be designed to be relatively flat, with their housing then having at least one flat wall area, which in the assembled state faces, for example, the underbody of the motor vehicle or even a roadway.

To reduce the fuel consumption of the motor vehicle using the muffler, it may be useful to reduce the vehicle weight as much as possible. Consequently, there is also a need for the silencer installed in a motor vehicle to produce it as easily as possible and consequently with reduced wall thicknesses. Here are housing problematic, which have as explained above at least a flat wall area. For the lower the wall thickness of such a flat wall area, the greater the tendency to Vibration excitation, which can lead to disturbing noises in the operation of the muffler and damage, in particular mechanical attachment points.

Against this background, the GB 2 352 480 A a silencer with a sandwich plate.

The WO 2012/055949 A1 discloses a silencer having a housing with a sandwich plate forming part of a housing shell.

The present invention addresses the problem of providing a muffler of the type mentioned an improved embodiment, which is particularly suitable for the realization of a lightweight construction. This problem is solved according to the invention by the subject matter of the independent claims. Advantageous embodiments are the subject of the dependent claims.

The muffler according to the invention has a sandwich plate, wherein this sandwich plate forms a part of a housing shell of the housing of the muffler. The muffler further comprises a self-supporting support structure, which in turn comprises a tube assembly which is at least partially disposed in the housing interior. This pipe arrangement may comprise, for example, an exhaust gas supply line and an exhaust gas discharge line, by means of which exhaust gas from an exhaust system of an internal combustion engine including the sound to be damped supplied to the muffler and can be discharged therefrom again. By means of the silencer according to the invention, both forces and mechanical bending moments, which are generated by the exhaust system of the internal combustion engine or of the internal combustion engine itself, are taken up by the pipe arrangement and passed through the silencer.

In this way, an undesirable introduction of such forces or mechanical bending moments in the actual housing of the muffler can be avoided, so that this in turn can be designed correspondingly thin-walled. By means of the self-supporting support structure, the tube assembly can be supported mechanically stable in the housing of the muffler.

From a supply line of the pipe assembly the muffler supplied forces or torques are thus transmitted directly through the self-supporting support structure to a discharge line of the pipe assembly and thus discharged again from the muffler without the housing of the muffler itself must absorb these forces. For connection of the muffler to a subfloor of a motor vehicle, the sandwich panel according to the invention can be used, which is flat for optimum attachment of the muffler to the subfloor and yet has a very high mechanical stability. Thus, the silencer according to the invention can also be mounted in the space in a motor vehicle usually spatially very limited space and, if necessary, this form correspondingly flat. Since the sandwich panel is composed of several (for example 4 to 5) individual sheet metal wall layers, each such sheet metal panel layer may have a thickness of about 0.1 mm, the total weight of such a sandwich panel compared to conventional sheet metal walls with a thickness of sheet metal wall 1.5 mm significantly reduced and thus particularly suitable for stiffening large areas. By using sandwich panels in silencers (instead of conventional sheet metal walls) can thus achieve a significant weight savings. The muffler according to the invention can consequently be manufactured in lightweight construction, it being ensured at the same time that the mechanical or mechanical bending moments required for the reception and transmission of the muffler are present.

According to the invention, the self-supporting support structure comprises at least one intermediate floor. Such an intermediate floor can be used to support the pipe arrangement on the self-supporting support structure and thus further improve the mechanical stability of the muffler.

According to the invention, the sandwich panel is part of the self-supporting support structure. This allows a particularly good transmission of forces or torques supplied to the muffler via the self-supporting support structure, for example to a discharge line of the pipe arrangement.

According to the invention, the muffler comprises a jacket hood, which completes the sandwich panel to the housing shell of the housing of the muffler according to the invention. This means that the entire housing of the muffler is formed by the sandwich plate and such a jacket cover. This allows a mechanically stable, yet technically very easy to manufacture muffler, so that the production cost of such a muffler can be kept relatively low.

In a further embodiment, it may be thought that the muffler has a first and a second end floor, which complete the housing shell to the housing. For this purpose, the first or second end floor can each be adhesively bonded, soldered or welded to the housing jacket, so that the housing jacket with the two end floors forms a gas-tight housing. Since the two end floors have no supporting function, these may also be preferably formed as a thin sheet metal walls. In a particularly easy to manufacture and also particularly lightweight embodiment, the jacket cover can be integrally connected to the first and / or to the second end floor. This means that the jacket hood as well as the first and second end floor form a single workpiece, which in the manner of a hood connected to the sandwich panel and in particular this welded can be. The jacket hood integrally connected to the first and second end floor can be designed in the manner of a shell.

In order to ensure a mechanically particularly stable attachment of the shell hood to the sandwich panel, in a particularly preferred embodiment, the shell hood in a longitudinal section of the muffler have two edge portions for attachment to the at least one sandwich panel, which, to the outside, away from the housing interior of the muffler , or inwards, towards the housing interior, stand out.

For the effective initiation of the sound to be damped by the silencer according to the invention, the first or / and second end floor of the silencer can each have a first or second through-opening. The crude arrangement may comprise at least one supply and discharge pipe with a supply or discharge opening, which are performed through the first and second through-openings from the outside into the housing interior, such that the supply or discharge opening in the at least a chamber of the muffler is arranged.

In order to further increase the mechanical stability of the silencer according to the invention, so that it can absorb particularly high forces or bending moments introduced into the silencer, the at least one intermediate bottom can have a first and a second end section, the first end section then being attached to the first sandwich panel and the second end portion can be supported on the further sandwich panel or on the jacket hood. At least one through-opening may be provided in the intermediate bottom in an area arranged between the two end sections, through which the at least one supply or discharge pipe can be made. In this way, the supply and discharge pipe can be mechanically supported particularly stable in the muffler.

In a particularly preferred embodiment, the at least one intermediate floor may be an additional sandwich panel (in addition to the first and second sandwich panels). In this case, a particularly high mechanical stability can be achieved in the silencer according to the invention by means of the additional sandwich plate. Alternatively, the at least one intermediate floor may also be a sheet metal wall. This variant is particularly preferable when the mechanical stability does not have to be substantially increased by means of the intermediate bottom, so that the sheet metal wall can serve, for example, as a pure partition for separating the chamber in the housing interior into a first and second sub-chamber, by means of which in Sound absorber introduced sound can be particularly well damped.

In a particularly simple and inexpensive to manufacture embodiment, the sandwich panel can be connected to the other sandwich panel or the jacket hood by means of welding, gluing or soldering.

In order to be able to fix the sandwich panel particularly well to the jacket hood, the at least one sandwich panel in a longitudinal section profile of the muffler may have a first and second end section with respect to the longitudinal direction, in which a wall thickness of the sandwich panel has a lower value than in one arranged between the two end sections Area of the sandwich panel. The sandwich panel can then be riveted to the two end portions with complementary to these two end portions edge portions of the jacket cover.

The invention further relates to an exhaust system, in particular for an internal combustion engine of a motor vehicle, with an exhaust gas removal pipe for discharging exhaust gas from the exhaust system and with a silencer with one or more of the aforementioned features. The tube assembly of the muffler may have a fluidically connected to the exhaust gas discharge pipe feed pipe.

The present invention further relates to an internal combustion engine having a combustion chamber and an exhaust system with one or more of the aforementioned features, wherein the combustion chamber of the internal combustion engine can be fluidly connected to the exhaust system by means of a connecting pipe.

Other important features and advantages of the invention will become apparent from the dependent claims, from the drawings and from the associated figure description with reference to the drawings.

A preferred embodiment of the invention is illustrated in the drawings and will be explained in more detail in the following description.

Fig. 1

ein erstes Ausführungsbeispiel eines erfindungsgemäßen Schalldämpfers in einer Längsschnittansicht,

Fig. 2

den Schalldämpfer der Figur 1 in einer Seitenansicht,

Fig. 3

eine nicht zur Erfindung gehörige Variante des Ausführungsbeispiels der Figur 1,

Fig. 4

eine Schnittansicht des Schalldämpfers der Figur 3 gemäß der Linie IV-IV,

Fig. 5

eine Schnittansicht des Schalldämpfers der Figur 3 gemäß der Linie V-V,

Fig. 6

eine Teilansicht der Figur 1,

Fig. 7

eine Variante der Figur 6,

Fig. 8

den erfindungsgemäßen Schalldämpfer als Teil einer Abgasanlage bzw. einer Brennkraftmaschine in einer grobschematischen Darstellung.

It show, each schematically:

Fig. 1

A first embodiment of a silencer according to the invention in a longitudinal sectional view,

Fig. 2

the silencer of FIG. 1 in a side view,

Fig. 3

a not belonging to the invention variant of the embodiment of the FIG. 1 .

Fig. 4

a sectional view of the muffler of FIG. 3 according to the line IV-IV,

Fig. 5

a sectional view of the muffler of FIG. 3 according to the line VV,

Fig. 6

a partial view of FIG. 1 .

Fig. 7

a variant of FIG. 6 .

Fig. 8

the silencer according to the invention as part of an exhaust system and an internal combustion engine in a rough schematic representation.

In the Figures 1 and 2 an inventive silencer is shown and designated 1. The FIG. 1 shows the muffler 1 while in a longitudinal sectional view, the FIG. 2 in a side view.

The silencer 1 comprises a housing 2, which has a housing jacket 3 extending in a circumferential direction U of the housing. The silencer 1 further comprises a housing interior 4 having at least one chamber 8, which is enclosed by the housing 2, as well as a self-supporting support structure 5 and a sandwich plate 6. The sandwich panel 6 forms a part of the housing shell 3. The self-supporting support structure 5 comprises a tube arrangement 7, which is arranged partially in the housing interior 4. The muffler 1 further comprises a jacket hood 9, which completes the first sandwich panel 6 to the housing shell 3 (see. FIG. 2 ). The sandwich panel 6 may be connected to the jacket hood 9 by means of welding, gluing or soldering.

Looking at the representation of the FIG. 2 , it can be seen that the jacket hood 9 due to their shell-like design completes the sandwich panel 6 not only to the housing shell 3, but to the entire housing 2. This means in particular that for the completion of the housing shell 3 no additional end floors are required, which greatly simplifies the construction and thus the production of the silencer 1 according to the invention. In an alternative approach, the shroud 9 may also be considered integral with first and second end bottoms.

In one in the FIG. 3 shown, not belonging to the invention variant of the embodiment of FIG. 1 the muffler 1 'as an alternative to the jacket hood 9, a further sandwich panel 10', which is part of the self-supporting support structure, and a first and a second metal wall 11 ', 12' include. These then complete together the first sandwich panel 6 'to the housing shell 3'. The FIG. 4 shows the muffler 1 'of FIG. 3 according to the section line IV, and the FIG. 5 shows the muffler 1 'according to the section line V.

The sandwich panel 6 'and the further sandwich panel 10' as well as the first and second panel wall 11 ', 12' may be arranged in the cross-sectional profile of the muffler 1 ', preferably substantially opposite one another. In principle, however, other arrangement geometries are also conceivable in further variants.

In the variant according to the FIGS. 3 to 5 not reflecting the invention, the first and second sheet metal walls 11 ', 12' simultaneously also form a first and a second end floor 13 ', 14', which complete the housing shell 3 'to the housing 2', ie the sheet metal walls 11 ' , 12 'and the end floors 13', 14 'are integrally connected to each other and form a frame-like structure in the manner of a circumferential U-profile (see. Fig. 4 and 5 ) out. In a variant, the sheet metal walls 11 ', 12' and the end floors 13 ', 14' but also each formed separately and welded together. The end floors 13 ', 14' or the metal walls 11 ', 12' can be glued or soldered to the sandwich panels 6 ', 10'.

Looking again at the representation of the Figures 1 and 2 , it can be seen that the jacket bottom 9 has a first or second through-opening 15, 16, and that the tube structure 7 of the muffler 1 comprises a supply and a discharge pipe 17, 18 with a supply or discharge opening 19, 20, which are performed by the first and second passage opening 15, 16 from the outside into the housing interior 4. The supply or discharge opening 19, 20 is arranged in the chamber 8. The same applies mutatis mutandis mutandis for the variant of the embodiment according to the FIGS. 3 to 5 , In this case, the first or second passage opening 15 ', 16' in the first and second end floor 13 ', 14' may be provided (see. Fig. 3 ).

To further improve the mechanical stability of the muffler 1, 1 'as in the FIGS. 1 . 3 and 5 shown two shelves 21, 21 ', each having a first and a second end portion 22, 23, 22', 23 ', wherein the first end portion 22, 22' on the first sandwich panel 6, 6 'and the second end portion 23, 23rd ', at the on the jacket hood 9 (see. Fig. 1 ) or on the second sandwich panel 10 '(cf. Fig. 4 ) is supported. The intermediate floors 21, 21 'can be glued or soldered to the sandwich panels 6, 6', 10 'and welded to the jacket hood 9, to the sheet metal walls 11', 12 'and to the end floors 13, 14'.

In the two intermediate floors 21, 21 ', passage openings 24, 24' are provided in a region arranged between the first and second end sections, through which passages or discharge pipes 17, 18, 17 ', 18' are made. It is clear that in variants also a different number of intermediate floors may be provided in the muffler 1,1 '.

In the presentation of the FIGS. 1 . 3 and 5 the intermediate floors 21, 21 'are formed as thin sheet metal walls. Depending on which additional mechanical stiffening is to be achieved by means of the additional shelves 21, 21 ', they can basically be designed either as a mechanically particularly stable sandwich panel or as a thin sheet-metal wall to be produced particularly inexpensively. Also, combinations such that individual shelves 21, 21 'as a thin sheet metal wall and other shelves 21, 21' are formed as sandwich panels are conceivable.

In variants of the exemplary embodiment, the at least one sandwich panel 6, 6 'or / and the at least one intermediate floor 21, 21' may be part of the self-supporting support structure 5.

From the representation of FIG. 1 It can be seen that the jacket hood 9 for particularly stable attachment to the sandwich panel 6 in a longitudinal section profile of the muffler 1 may have two edge portions 25 which project outwardly away from the housing interior 4. In an alternative variant, the edge portions 25 of course also inwardly, the housing interior 4 out, stand out.

Alternatively or additionally, the sandwich panel 6, 6 'in the longitudinal section profile of the muffler 1 have a first and second end portion 26 with respect to a longitudinal direction L of the muffler 1 in which a wall thickness D of the sandwich panel 6 is lower than D ₁ This is roughly schematic in the representation of the FIG. 6 shown, which shows the sandwich plate 6 with an end portion 26. In a variant, the end portions 26 may also be formed as folded portions which surround the edge portions 25 of the jacket hood 9. This is roughly schematic in the FIG. 7 shown. In the area of the end sections 26, the jacket hood 9 can then additionally be fastened to the sandwich panel 6 by gluing or soldering. Alternatively, it is of course also conceivable that the edge portions 25 of the jacket hood 9 are formed as folded portions which engage around the end portions 26 of the sandwich panel 6.

As the presentation of the FIG. 6 can be, the sandwich panel 6 for the purpose of a particularly stable attachment to the jacket hood 9 in the region 25 or 26 riveted (see reference numeral 32 in the FIG. 6 ).

In the rough schematic representation of FIG. 8 It is shown that the muffler 1 can be part of an exhaust system 27, in particular for an internal combustion engine of a motor vehicle, which in turn can be equipped with an exhaust gas exhaust pipe 30 for discharging exhaust gas from the exhaust system 27. The exhaust gas removal pipe 30 is fluidly connected to the supply pipe 17 of the muffler 1. The exhaust system 27 in turn may be part of an internal combustion engine 28 having a combustion chamber 29, wherein the combustion chamber 29 of the internal combustion engine 28 is fluidly connected to the exhaust system 27 by means of a connecting pipe 31.

Claims (6)

1. A silencer (1) for an exhaust system of an internal combustion engine, in particular of a motor vehicle, the silencer (1) comprising:

   - a housing (2) which comprises a housing shell (3) extending in a circumferential direction (U) of the housing (2),

   - a sandwich plate (6), which forms part of the housing shell (3),

   - a housing interior space (4) comprising at least one chamber (8), which is enclosed by the housing (2),

   - a self-supporting support structure (5) which comprises a pipe arrangement (7) at least partially arranged in the housing interior space (4),

   - wherein the self-supporting support structure (5) comprises at least one intermediate floor (21),

   - wherein the at least one sandwich plate (6) is part of the self-supporting support structure (5),

   characterized in that

   - the silencer (1) comprises a shell hood (9) which completes the sandwich plate (6) to form the housing shell (3).
2. The silencer (1) according to claim 1,
   characterized in that
   the shell hood (9) in a longitudinal section profile of the silencer (1) comprises two marginal portions (25) for attaching to the at least one sandwich plate (6), which project to the outside, away from the housing interior space (4), or to the inside, towards the housing interior space (4).
3. The silencer (1) according to any one of preceding claims,
   characterized in that the at least one intermediate floor (21) is an additional sandwich plate or a sheet metal wall.
4. The silencer (1) according to any one of the preceding claims,
   characterized in that

   - the at least one sandwich plate (6) in a longitudinal section profile of the silencer (1) comprises an with respect to the longitudinal direction (L) first and second end portion (26), in which a wall thickness (D) of the sandwich plate (6) has a lower value (D₁) than in a region of the sandwich plate (6) arranged between the two end portions (26),

   - the at least one sandwich plate (6) on the two end portions (26) is riveted to the marginal portions (25) of the shell hood (9) which is complementary to these two end portions (26).
5. An exhaust gas system (27), in particular for an internal combustion engine (28) of a motor vehicle, comprising:

   - an exhaust gas discharge pipe (30) for discharging exhaust gas from the exhaust gas system (27),

   - a silencer (1) according to any one of the preceding claims,

   - wherein the pipe arrangement (7) comprises a feed pipe (17) which is fluidically connected to the exhaust gas discharge pipe (30).
6. An internal combustion engine (28), comprising:

   - a combustion chamber (29),

   - an exhaust gas system (27) according to Claim 5,

   - wherein the combustion chamber (29) is fluidically connected to the exhaust gas system (27) by means of a connecting pipe (31).

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